Dunkin' is offering a FREE Medium Cold Brew to new members that join the DD Perks program. As a member, you also get a Free Beverage of your choice in any size every year on your birthday plus many other sweet perks throughout the year! Click here to sign up a new member then confirm your mobile number to complete sign up. Your free cold brew offer must be redeemed within 7 days of enrolling in DD Perks. Your free birthday drink coupon will be loaded to your account around your birthday.